Professor Stephen Jay Gould, who has died of cancer aged 60, was an unlikely figure to have been canonised by the US congress, which named him as one of America’s “living legends”. A palaeontologist, he was based for most of his life at the museum of comparative zoology (MCZ) at Harvard. But he was best known for his unbroken sequence of 300 monthly essays in Natural History magazine and republished in a seemingly unending stream of books.

A stylish writer, Gould characterised each essay by deriving a seemingly abstruse point in natural history or palaeontology via a sideways look at a novel, a building, or, often, a reference to his lifelong enthusiasm for baseball. He once illuminated the peculiar evolutionary phenomenon in which more recently evolved species within a family group steadily decrease in size by comparing it to how the manufacturers of Hershey bars avoided price rises by making the bars smaller.

As a scientific essayist, Gould’s only peers were “Darwin’s bulldog”, Thomas Huxley, in the 19th century and JBS Haldane in the 1930s and 1940s. The comparison with Haldane is apt – both made fundamental contributions to evolutionary theory, and both were politically engaged. Gould’s critique of the pseudoscience of claims concerning the inheritance of intelligence, developed in his book, The Mismeasure Of Man (1981), became a major source for anti-racist campaigners.

As a major public intellectual and powerful public speaker, Gould could be seen at demonstrations and on picket lines, especially during the 1960s and 70s. This was the birth of what became known as the radical science movement (Science for the People), initially in response to the Vietnam War. The movement, and Gould along with it, later became embroiled in the cultural fights that raged around E.O. Wilson’s Sociobiology (1975), the forerunner to today’s evolutionary psychology, and seen by many as offering a scientific validation for social inequalities in class, gender and race.

For Gould the issues were never just about politics, but also about a different view of the mechanisms and processes of evolution, a view that reached its clearest expression in his last and greatest book, The Structure Of Evolutionary Theory – published only last month. This is the most comprehensive statement of Gould’s Darwinian revisionism, which began when he and Niles Eldredge developed their critique of one of Darwin’s central theses, that of gradual evolutionary change.

Gould and Eldredge pointed out that the fossil record was one of millions of years of stasis, punctuated by relatively brief periods of rapid change – hence punctuated equilibrium. To Gould’s fury, as a loyal child of Darwin, the theory was misappropriated by creationists, whom he attacked with vigour. However, in one of his most recent books, Rocks Of Ages (1999), he attempted to come to terms with a religion more reconciled to science, reversing the proposition of rendering unto Caesar by allowing religion its independent domain. But punctuated equilibrium made many traditional evolutionists unhappy too; they saw it as evidence of Gould’s alleged Marxism – revolution rather than evolution.

Orthodox biologists also tended to resent the insouciance with which Gould upstaged them. Lecturing at the Royal Society in London in the 1970s, he treated the assembled grandees to an account of the architecture of the San Marco cathedral in Venice, to make the point that many seemingly adaptive features of an organism are, in fact, the byproducts of more fundamental structural constraints. The mosaic-filled spaces (spandrels) between the arches on which the dome stands may look as if they were planned – but they are merely space-fillers. Many features of an organism (its phenotype) may also be structural spandrels, others may be “exaptations” – another term coined by Gould, with Elizabeth Vrba, to describe features arising in one context but subsequently put to a different use. The Structure Of Evolutionary Theory is a robust and formidable defence of his key contributions to Darwinian revisionism. Evolution is not a la carte, but structurally constrained; not all phenotypic features are adaptive, but may instead be spandrels or exaptations – or even contingent accidents, like the asteroid collision believed to have wiped out the dinosaurs, thus making space for mammals and ultimately humans. Chance is crucial, and there is nothing inherently progressive about evolution – no drive to perfection, complexity or intelligent life.

Above all, he argues, natural selection works at many levels. Because genetics has come to dominate much of the life sciences, for many biologists organisms have become almost irrelevant, save as instruments serving the purposes of their genes – splendidly encapsulated in Richard Dawkins’ famous description of humans as “lumbering robots” – the gene’s way of making copies of itself. Evolution itself has come to be defined as a change in gene frequency in a population. By contrast, Gould argues for a hierarchical view; that evolution works on genes, genomes, cell lineages and, especially, on species. Ignoring speciation, he says, is like playing Hamlet without the prince. This is the central theoretical issue underlying all the polemics that characterise what have come to be known as the “Darwin wars”, pitting Gould against Dawkins, although in reality – and to the chagrin of creationists – both are children of Darwin, and agree on far more than they disagree.

Born in Queens, New York, and educated through the city’s superb public school system, Gould trained as a geologist at Antioch College, Ohio, took a doctorate in palaeontology at Columbia University, New York, in 1967, and spent a brief period at Leeds University before moving to Harvard. In 1982, he was diagnosed with mesothelioma, rumoured to have been precipitated by the asbestos lining of the specimen cabinets in the MCZ basement. The disease has a median survival time of eight months but Gould wrote he was committed to being one of those who survived long enough to help show that statistic medians are not means after all. The 20 years before cancer finally caught up with him were packed with more than most public intellectuals and scientists can hope to achieve in a lifetime, and a small galaxy of prizes. He was married twice, and is survived by his former wife Deborah, their sons Jesse and Ethan, his second wife Rhonda, and his stepchildren, Jade and London.